03 · What You Need to Know
What Determines Consistency When AI Codes Large Text Datasets?
What Does Consistent AI Coding Actually Mean?
Consistency can refer to several different properties of a coding workflow. These should not be treated as interchangeable.
| Type of Consistency |
What It Means |
Example |
| Within-run consistency |
Comparable responses receive comparable classifications during one processing run. |
Two responses describing unstable internet access receive the same connectivity code. |
| Between-batch consistency |
The coding rules are applied similarly across separately processed groups of responses. |
Responses in the first and final batches follow the same category definitions. |
| Repeat-run stability |
The same response receives the same classification when the procedure is repeated. |
Reprocessing an identical response produces an unchanged code. |
| Codebook adherence |
Assignments follow the specified category definitions and decision rules. |
The model distinguishes internet connectivity from platform usability according to the codebook. |
A workflow may perform well on one dimension but poorly on another. For example, a model could assign the same code during repeated runs while consistently misunderstanding the code's intended definition.
Researchers should distinguish these operational properties from the validity of AI coding decisions, which concerns whether the classifications adequately represent the concepts being studied.
Can AI Really Process Thousands of Responses?
Yes, language models can be incorporated into workflows that classify large collections of text. However, processing thousands of records typically requires managing input size, output limits, service capacity, and the structure of individual requests.
Gilardi, Alizadeh, and Kubli (2023) evaluated ChatGPT on text-annotation tasks involving 6,183 tweets and news articles across four datasets. Their study found that ChatGPT outperformed crowd workers on several evaluated tasks and demonstrated the potential of language models for scalable annotation.
Importantly, the researchers submitted texts individually in separate chat sessions rather than relying on one enormous conversation. Their procedure illustrates how large-scale annotation can be organized as many controlled classification operations. It does not establish that submitting thousands of responses together would produce equivalent results.
The study also concerned specific annotation tasks, including relevance, stance, topics, and frame detection. Its findings should not be generalized automatically to every qualitative research methodology or coding framework.
Why Does Batch Processing Matter?
Batch processing means dividing a dataset into smaller groups that can be handled separately. A researcher with 10,000 responses might process them in groups of 50, 100, or another technically suitable size.
There is no universally optimal batch size. The appropriate choice depends on response length, codebook complexity, model limits, output requirements, and observed performance.
Batching creates practical advantages because researchers can track progress, identify failed requests, and rerun incomplete portions of the dataset. It also creates a potential source of inconsistency if the instructions or processing context differ between batches.
Operational completeness
Every intended record is processed and receives an output or an explicit failure status.
Analytical consistency
Comparable records are classified according to the same coding definitions and decision rules.
A workflow can be operationally complete without being analytically consistent. Conversely, a model might classify the records it processes consistently while silently omitting some responses.
Can the Same Response Receive Different Codes in Different Batches?
It can. When a model receives several responses together, the surrounding text may influence how it interprets an individual response. The prompt, previous conversational context, and available category examples can also affect the output.
Consider the statement: "I cannot keep up with the lessons."
When presented alongside responses about unreliable internet, a model might associate the statement with connectivity difficulties. When presented alongside responses about demanding assignments, it might interpret the same statement as a workload concern.
Neither classification is adequately supported by the isolated statement. The proper decision may be to flag the response as ambiguous unless additional context is available.
This example illustrates why researchers should not assume that identical wording will always receive identical treatment across changing input contexts.
One way to investigate this risk is to include selected benchmark responses across different processing conditions and compare their assignments. Such testing can reveal context sensitivity, although it cannot guarantee that every untested response will behave similarly.
Should Researchers Use One Long Chat Conversation or Separate Requests?
For large-scale structured classification, separate, controlled requests are often easier to document and evaluate than an extended conversation in which the model accumulates changing context.
A long conversation may include earlier examples, corrections, or instructions that influence later outputs. If these changes are not documented, responses processed at different stages may effectively receive different coding instructions.
Using independent requests with the same approved codebook and instructions can reduce this particular source of variation. However, separate requests do not eliminate model variability or guarantee correct classification.
Researchers should choose a workflow that permits clear identification of the instructions, codebook version, input records, and outputs associated with each processing operation.
Can AI Change Its Coding Decisions Even When the Prompt Stays the Same?
Yes. Generative models may produce different classifications across repeated executions. The extent of variation depends on the model, generation settings, service configuration, and task.
Some systems provide settings intended to reduce output variability. However, more deterministic settings do not necessarily guarantee identical results, particularly when the underlying service or model changes.
Researchers should therefore distinguish the stability of the coding instructions from the stability of the generated outputs.
The question of whether AI coding changes when a prompt is rerun requires direct testing rather than assumptions about model settings.
What Happens When the Codebook Changes During Processing?
A common source of inconsistency is changing category definitions after part of the dataset has already been coded.
Suppose the initial codebook uses a broad category called "technical problems." After processing 3,000 responses, the researcher decides to separate internet connectivity, device limitations, and platform usability.
The remaining 7,000 responses are then processed using the revised framework. Unless the earlier material is reconsidered, the dataset contains classifications produced under different category definitions.
The appropriate response is to document the revision and determine whether previously processed material must be recoded under the updated framework.
A controlled workflow should therefore maintain explicit codebook versions. Researchers should not assume that providing the same category names means the underlying definitions have remained unchanged.
How Can Researchers Detect Missing or Duplicated Responses?
Large-scale processing introduces data-management problems that are separate from semantic classification.
Each response should have a stable identifier before coding begins. The output should preserve that identifier so researchers can match every classification to the original record.
After processing, researchers should verify that the number of unique output identifiers matches the intended number of input records, accounting for documented exclusions and failures.
Researchers should separately report successful classifications, unresolved cases, and processing failures. A dataset containing 10,000 output rows may still contain duplicated identifiers or missing original responses.
How Can Researchers Evaluate Consistency Across Batches?
Several complementary checks may be useful.
-
Repeated benchmark cases: Submit selected responses under different batch conditions and compare their assignments.
-
Category-level monitoring: Examine whether the distribution of codes changes unexpectedly across batches.
-
Independent reference coding: Compare AI outputs with human-reviewed classifications using a sample designed to represent the relevant categories and difficult cases.
-
Error analysis: Investigate whether particular codes, response types, or linguistic patterns are repeatedly misclassified.
-
Record reconciliation: Confirm that every eligible input has a traceable processing outcome.
Unexpected differences between batches warrant investigation, but they do not automatically prove inconsistency. If different batches contain respondents from different institutions or populations, genuine differences in the data may explain changes in category frequencies.
Researchers should distinguish shifts caused by the composition of the dataset from shifts caused by model behavior.
Does Consistency Become More Important as the Dataset Grows?
Large datasets can make small systematic classification errors consequential. If a model repeatedly confuses two categories, the resulting frequencies may be distorted across thousands of records.
For example, suppose a model frequently classifies statements about institutional scheduling requirements as individual time-management problems. If that error occurs systematically, the final analysis could overstate student-level difficulties while understating institutional constraints.
The problem is not necessarily that the model becomes less accurate as the dataset grows. Rather, repeated errors can accumulate and influence aggregate findings.
Researchers should therefore examine systematic bias in AI coding, especially when categories influence policy recommendations, group comparisons, or interpretations of institutional responsibility.
What Does Research Evidence Say About Large-Scale AI Coding?
Gilardi and colleagues (2023) provide direct evidence that language models can be used for substantial text-annotation workloads. Their evaluation included 6,183 documents and found strong performance relative to crowd workers in the studied tasks. The researchers also evaluated repeated classifications under different temperature settings, providing a useful example of assessing agreement rather than assuming it.
However, their results do not establish that every coding task can achieve comparable accuracy or that larger workloads automatically preserve classification quality.
Parfenova and colleagues (2025) examined inductive coding by six open-source language models compared with human experts. Their findings suggest that model performance can be sensitive to the complexity of the material, reinforcing the importance of evaluating difficult responses rather than relying only on straightforward examples.
These studies support the feasibility of AI-assisted text annotation while leaving the researcher responsible for demonstrating whether a particular workflow performs adequately on its intended dataset.
How Should Large-Scale AI Coding Be Documented?
A defensible record should include the model or service used, available model version information, codebook version, prompts, relevant generation settings, preprocessing procedures, batch identifiers, processing dates, and validation results.
Researchers should retain the original responses, final coding assignments, and a record of any corrected or unresolved classifications. Where possible, they should also preserve the raw model outputs to investigate unexpected behavior.
These records support reproducibility in AI-assisted data coding. They do not guarantee that an external model service will remain unchanged or that future executions will reproduce identical outputs.
For sensitive research material, data retention and storage arrangements must remain consistent with consent, ethics approval, institutional requirements, applicable law, and relevant confidentiality obligations.
04 · A Practical Example
Evaluating AI Coding Consistency Across 10,000 Survey Responses
Hypothetical Example
A Multi-University Survey of Online Learning Challenges
A researcher collects 10,000 usable open-ended responses from students across several universities. The approved codebook contains six categories, including internet connectivity, platform usability, instructor communication, scheduling constraints, learning environment, and assessment difficulties.
The researcher wants to determine whether an AI-assisted workflow can classify the responses consistently while preserving traceability and supporting appropriate human verification.
Step 1: Prepare the Dataset
Each response receives a unique identifier. The researcher checks for missing text, duplicates, and records requiring special handling.
The codebook and classification instructions are finalized for the initial evaluation. Multiple codes are permitted when supported by the response.
Step 2: Pilot Different Processing Conditions
The researcher tests the procedure on varied responses, including straightforward statements, overlapping concerns, and ambiguous answers.
Different batch sizes are compared to determine whether the processing arrangement affects record completeness or classification behavior. The researcher also evaluates whether the model follows the approved category definitions.
The chosen batch size is based on observed technical performance and coding quality, not on an assumption that larger or smaller batches are inherently more accurate.
Step 3: Process the Full Dataset
Suppose the researcher chooses batches of 100 responses, resulting in 100 planned batches. The same approved codebook and instructions are supplied for each batch.
The system records each batch identifier, its input response identifiers, processing status, and output. Failed batches are handled through a documented retry procedure.
Step 4: Compare Benchmark Responses Across Batches
The researcher includes selected benchmark responses under controlled test conditions to investigate whether the same statements receive consistent assignments.
Suppose 200 repeated benchmark comparisons produce 184 identical code assignments and 16 differences.
The researcher examines the 16 disagreements to determine whether they involve ambiguous responses, overlapping categories, or differences associated with processing context.
Step 5: Examine Category-Specific Errors
Suppose the researcher finds that most disagreements concern scheduling constraints and time-related learning difficulties.
Closer examination reveals that some responses describe conflicts imposed by institutional schedules, while others concern individual difficulties organizing study time.
The researcher reviews the codebook definitions and determines whether the distinction is sufficiently clear. Any justified revision is documented and evaluated using additional material before the affected coding is finalized.
Step 6: Verify the Final Dataset
Before analysis, the researcher confirms that all 10,000 eligible responses have traceable outcomes and that unresolved or failed classifications are identified.
An appropriately designed human-review procedure examines coding accuracy, difficult cases, and potential systematic errors. The researcher then uses the verified data for descriptive analysis.
The workflow demonstrates consistency through observed evidence rather than assuming that standardized prompts automatically produce standardized decisions.